package com.itheima.interceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import com.itheima.po.User;
/**
 * 登录拦截器
 */
public class LoginInterceptor implements HandlerInterceptor{
	@Override
	public boolean preHandle(HttpServletRequest request, 
		HttpServletResponse response, Object handler) throws Exception {
	    // 获取请求的URL  
        String url = request.getRequestURI();  
        // URL:除了login.jsp是可以公开访问的，其它的URL都进行拦截控制  
        if(url.indexOf("/login")>=0){  
            return true;  
        }  
        // 获取Session  
        HttpSession session = request.getSession();  
        User user = (User) session.getAttribute("USER_SESSION");
        // 判断Session中是否有用户数据，如果有，则返回true,继续向下执行
        if(user != null){
            return true;  
        }
         // 不符合条件的给出提示信息，并转发到登录页面
         request.setAttribute("msg", "您还没有登录，请先登录！");
         request.getRequestDispatcher("/WEB-INF/jsp/login.jsp")
                                                .forward(request, response);
		return false;
	}
	@Override
	public void postHandle(HttpServletRequest request, 
			HttpServletResponse response, Object handler,
			ModelAndView modelAndView) throws Exception {
	}
	@Override
	public void afterCompletion(HttpServletRequest request, 
			HttpServletResponse response, Object handler, Exception ex)
			throws Exception {
	}
}
